<template>
  <view class="imageUploadContainer">
    <view class="imageUploadList">
      <view class="imageItem" v-bind:key="index" v-for="(path, index) in imageListData">
        <image :src="path" :class="{ dragging: isDragging(index) }" :draggable="true" @tap="previewImage" :data-index="index" @touchstart="start" @touchmove.stop.prevent="move" @touchend="stop"></image>
        <view v-if="isShowDel" class="imageDel" @tap="deleteImage" :data-index="index">
          <image class="closeImg" src="./close.png" alt=""></image>
        </view>
      </view>
      <view v-if="isShowAdd" class="imageUpload" @tap="selectImage">+</view>
    </view>
    <image v-if="showMoveImage" class="moveImage" :style="{ left: posMoveImageLeft, top: posMoveImageTop }" :src="moveImagePath"></image>
  </view>
</template>

<script>
export default {
  name: "robby-image-upload",
  props: [
    "value",
    "enableDel",
    "enableAdd",
    "enableDrag",
    "serverUrl",
    "formData",
    "header",
    "limit",
    "fileKeyName",
    "serverUrlDeleteImage",
  ],
  data () {
    return {
      imageBasePos: {
        x0: -1,
        y0: -1,
        w: -1,
        h: -1,
      },
      showMoveImage: false,
      moveImagePath: "",
      moveLeft: 0,
      moveTop: 0,
      deltaLeft: 0,
      deltaTop: 0,
      dragIndex: null,
      targetImageIndex: null,
      imageList: [],
      isDestroyed: false,
    };
  },
  mounted: function () {
    this.imageList = this.value;

    if (this.showUploadProgress === false) {
      this.showUploadProgress = false;
    } else {
      this.showUploadProgress = true;
    }
  },
  destroyed: function () {
    this.isDestroyed = true;
  },
  computed: {
    imageListData: function () {
      if (this.value) {
        let data = [];
        this.value.forEach((element) => {
          this.$set(data, data.length, 'https://csct.yhxxfw.cn:8086/server/profile/' + JSON.parse(element).url);
        });
        return data;
      }
    },
    posMoveImageLeft: function () {
      return this.moveLeft + "px";
    },
    posMoveImageTop: function () {
      return this.moveTop + "px";
    },
    isShowDel: function () {
      if (this.enableDel === false) {
        return false;
      } else {
        return true;
      }
    },
    isShowAdd: function () {
      if (this.enableAdd === false) {
        return false;
      }

      if (this.limit && this.imageList.length >= this.limit) {
        return false;
      }

      return true;
    },
    isDragable: function () {
      if (this.enableDrag === false) {
        return false;
      } else {
        return true;
      }
    },
  },
  methods: {
    selectImage: function () {
      var _self = this;
      if (!_self.imageList) {
        _self.imageList = [];
      }

      uni.chooseImage({
        count: _self.limit ? _self.limit - _self.imageList.length : 999,
        success: function (e) {
          var imagePathArr = e.tempFilePaths;

          //如果设置了limit限制，在web上count参数无效，这里做判断控制选择的数量是否合要求
          //在非微信小程序里，虽然可以选多张，但选择的结果会被截掉
          //在app里，会自动做选择数量的限制
          if (_self.limit) {
            var availableImageNumber = _self.limit - _self.imageList.length;
            if (availableImageNumber < imagePathArr.length) {
              uni.showToast({
                title:
                  "图片总数限制为" +
                  _self.limit +
                  "张，当前还可以选" +
                  availableImageNumber +
                  "张",
                icon: "none",
                mask: false,
                duration: 2000,
              });
              return;
            }
          }

          //检查服务器地址是否设置，设置即表示图片要上传到服务器
          if (_self.serverUrl) {
            // uni.showToast({
            //   title: "上传进度：0/" + imagePathArr.length,
            //   icon: "none",
            //   mask: false,
            // });
            uni.showLoading({
              title: '上传中：0/' + imagePathArr.length
            });
            var remoteIndexStart = _self.imageList.length - imagePathArr.length;
            var promiseWorkList = [];
            var keyname = _self.fileKeyName ? _self.fileKeyName : "file";
            var completeImages = 0;

            for (let i = 0; i < imagePathArr.length; i++) {
              promiseWorkList.push(
                new Promise((resolve, reject) => {
                  let remoteUrlIndex = remoteIndexStart + i;
                  uni.uploadFile({
                    url: _self.serverUrl,
                    fileType: "image",
                    header: _self.header,
                    formData: _self.formData,
                    filePath: imagePathArr[i],
                    name: keyname,
                    success: function (res) {
                      if (res.statusCode === 200) {
                        if (_self.isDestroyed) {
                          return;
                        }

                        completeImages++;

                        if (_self.showUploadProgress) {
                          uni.hideLoading();
                          uni.showToast({
                            title:
                              "上传进度：" +
                              completeImages +
                              "/" +
                              imagePathArr.length,
                            icon: "none",
                            mask: false,
                            duration: 500,
                          });
                        }
                        console.log("success to upload image: " + res.data);
                        resolve(res.data);
                      } else {
                        console.log("fail to upload image:" + res.data);
                        reject("fail to upload image:" + remoteUrlIndex);
                      }
                    },
                    fail: function (res) {
                      console.log("fail to upload image:" + res);
                      reject("fail to upload image:" + remoteUrlIndex);
                    },
                  });
                })
              );
            }
            Promise.all(promiseWorkList).then((result) => {
              if (_self.isDestroyed) {
                return;
              }

              for (let i = 0; i < result.length; i++) {
                _self.imageList.push(result[i]);
              }

              _self.$emit("add", {
                currentImages: imagePathArr,
                allImages: _self.imageList,
              });
              _self.$emit("input", _self.imageList);
            });

          } else {
            for (let i = 0; i < imagePathArr.length; i++) {
              _self.imageList.push(imagePathArr[i]);
            }

            _self.$emit("add", {
              currentImages: imagePathArr,
              allImages: _self.imageList,
            });
            _self.$emit("input", _self.imageList);
          }
        },
      });
    },
    deleteImage: function (e) {
      var imageIndex = e.currentTarget.dataset.index;
      var deletedImagePath = this.imageList[imageIndex];
      this.imageList.splice(imageIndex, 1);

      //检查删除图片的服务器地址是否设置，如果设置则调用API，在服务器端删除该图片
      if (this.serverUrlDeleteImage) {
        uni.request({
          url: this.serverUrlDeleteImage,
          method: "GET",
          data: {
            imagePath: deletedImagePath,
          },
          success: (res) => {
            console.log(res.data);
          },
        });
      }

      this.$emit("delete", {
        currentImage: deletedImagePath,
        allImages: this.imageList,
      });
      this.$emit("input", this.imageList);
    },
    previewImage: function (e) {
      // alert('图片预览')
      var imageIndex = e.currentTarget.dataset.index;
      var initImageUrl = []
      this.imageList.forEach((element) => {
        let ele = JSON.parse(element)
        this.$set(initImageUrl, initImageUrl.length, 'https://csct.yhxxfw.cn:8086/server/profile/' + ele.url);
      });
      uni.previewImage({
        current: initImageUrl[imageIndex],
        indicator: "number",
        loop: "true",
        urls: initImageUrl,
      });
    },
    initImageBasePos: function () {
      let paddingRate = 0.024;
      var _self = this;
      //计算图片基准位置
      uni.getSystemInfo({
        success: function (obj) {
          let screenWidth = obj.screenWidth;
          let leftPadding = Math.ceil(paddingRate * screenWidth);
          let imageWidth = Math.ceil((screenWidth - 2 * leftPadding) / 4);

          _self.imageBasePos.x0 = leftPadding;
          _self.imageBasePos.w = imageWidth;
          _self.imageBasePos.h = imageWidth;
        },
      });
    },
    findOverlapImage: function (posX, posY) {
      let rows = Math.floor(
        (posX - this.imageBasePos.x0) / this.imageBasePos.w
      );
      let cols = Math.floor(
        (posY - this.imageBasePos.y0) / this.imageBasePos.h
      );
      let indx = cols * 4 + rows;
      return indx;
    },
    isDragging: function (indx) {
      return this.dragIndex === indx;
    },
    start: function (e) {
      console.log(this.isDragable);
      if (!this.isDragable) {
        return;
      }
      this.dragIndex = e.currentTarget.dataset.index;
      this.moveImagePath = this.imageList[this.dragIndex];
      this.showMoveImage = true;

      //计算纵向图片基准位置
      if (this.imageBasePos.y0 === -1) {
        this.initImageBasePos();

        let basePosY = Math.floor(this.dragIndex / 4) * this.imageBasePos.h;
        let currentImageOffsetTop = e.currentTarget.offsetTop;
        this.imageBasePos.y0 = currentImageOffsetTop - basePosY;
      }

      //设置选中图片当前左上角的坐标
      this.moveLeft = e.target.offsetLeft;
      this.moveTop = e.target.offsetTop;
    },
    move: function (e) {
      if (!this.isDragable) {
        return;
      }
      const touch = e.touches[0];
      this.targetImageIndex = this.findOverlapImage(
        touch.clientX,
        touch.clientY
      );

      //初始化deltaLeft/deltaTop
      if (this.deltaLeft === 0) {
        this.deltaLeft = touch.clientX - this.moveLeft;
        this.deltaTop = touch.clientY - this.moveTop;
      }

      //设置移动图片位置
      this.moveLeft = touch.clientX - this.deltaLeft;
      this.moveTop = touch.clientY - this.deltaTop;
    },
    stop: function (e) {
      if (!this.isDragable) {
        return;
      }
      if (this.dragIndex !== null && this.targetImageIndex !== null) {
        if (this.targetImageIndex < 0) {
          this.targetImageIndex = 0;
        }

        if (this.targetImageIndex >= this.imageList.length) {
          this.targetImageIndex = this.imageList.length - 1;
        }
        //交换图片
        if (this.dragIndex !== this.targetImageIndex) {
          this.imageList[this.dragIndex] =
            this.imageList[this.targetImageIndex];
          this.imageList[this.targetImageIndex] = this.moveImagePath;
        }
      }

      this.dragIndex = null;
      this.targetImageIndex = null;
      this.deltaLeft = 0;
      this.deltaTop = 0;
      this.showMoveImage = false;

      this.$emit("input", this.imageList);
    },
  },
};
</script>

<style>
/* .imageUploadContainer {
  padding: 10upx 5upx;
  margin: 10upx 5upx;
} */

.dragging {
  transform: scale(1.2);
}

.imageUploadList {
  display: flex;
  flex-wrap: wrap;
}

.imageItem,
.imageUpload {
  width: 160upx;
  height: 160upx;
  margin: 24upx 4upx;
}

.imageDel {
  position: relative;
  left: 124upx;
  bottom: 184upx;
  border-radius: 50%;
}
.closeImg {
  width: 50upx !important;
  height: 50upx !important;
}

.imageItem image,
.moveImage {
  width: 160upx;
  height: 160upx;
  border-radius: 8upx;
}

.imageUpload {
  line-height: 130upx;
  text-align: center;
  font-size: 150upx;
  color: #d9d9d9;
  border: 1px solid #d9d9d9;
  border-radius: 8upx;
}

.moveImage {
  position: absolute;
}
</style>